5,210 research outputs found

    Titanium Carbide: Nanotechnology, Properties, Application

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    The paper develops scientific and technological bases for fabrication of titanium carbide which is a nanocomponent of composite materials. The authors determine optimum technology specifications and the main titanium carbide properties: fineness of titaniferous raw materials, carbide-forming agent quantity, set temperature of plasma flow, tempering temperature, titanium carbide yield, productivity, specific surface, size and shape of particles. The paper includes equations to describe how the major specifications of the fabrication technique influence the content of titanium carbide and free carbon in the end product

    Thin structure of steel St52, 3N and possible reasons of defect of large-capacity billets AT "YURMASH"

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    Electron-microscopic and x-ray investigations of structurally-phase and intense-deformed condition of material made of defective and conditional forged billet at «Yurmash» have been carried out. It is ascertained that in steel made from the defective forged piece the fraction of perlite is 1,5...2 times higher and lamellar perlite prevails. Local long-range tensions in both conditions of material are commensurable with fluidity limit. The content of sulfides is considerably higher in the steel made from the defective billet. They are located in the body of ferrite grains and along the interfaces. In the material made from the conditional forging they are located only inside of grains. The scalar density of dislocations in ferrite grains and in ferrite layers of perlite of the defected billet is one and a half time higher than in conditional metal. All the totality of the listed above circumstances allows stating that the main cause of cracking of large-capacity billets made of steel St52, 3N is not a full conformity of the chemical compound to branded requirements

    Testing standard-model extensions with isotope shifts in few-electron ions

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    When collecting spectroscopic data on at least four isotopes, nonlinearitiesin the King plot are a possible sign of Physics beyond the Standard Model. Inthis work, an improved approach to the search for hypothetical new interactionswith isotope shift spectroscopy of few-electron ions is presented. Very carefulaccount is taken of the small nuclear corrections to the energy levels and thegyromagnetic factors, which cause deviations from King linearity within theStandard Model and are hence a possible source of confounds. In this newapproach, the experimental King nonlinearity is not compared to the vanishingprediction of the Standard Model at the leading order, but to the calculatedfull Standard Model contribution to King nonlinearity. This makes searching forbeyond-the-Standard-Model physics with King linearity analysis possible in avery-high-precision experimental regime, avoiding confounds. The bounds whichcan be set on beyond-the-Standard-Model parameters remain limited by theuncertainties on the small Standard Model nuclear corrections which cause Kingnonlinearity. Direct comparison between theory and experiment on a single pairof isotopes is advocated as a more suitable approach for few-electron ions.<br

    Alloying Elements Transition Into the Weld Metal When Using an Inventor Power Source

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    The temperature distribution over the surface of the welded 12Kh18N10T steel plates using the inventor power source ARC-200 has been calculated. In order to imitate multipass welding when conducting the thermal analysis the initial temperature was changed from 298K up to 798K in 100K increments. It has been determined that alloying elements transition into the weld metal depends on temperature. Using an inventor power source facilitates a uniform distribution of alloying elements along the length and height of the weld seam

    Some Aspects of Oxidation-Reduction Reactions under Carbon-Bearing Flux Welding

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    The authors have completed thermodynamic calculations of oxidation-reduction processes under submerged arc welding with application of carbon containing additive. The calculations have shown that carbon, due to its high reducing properties under Т=1950-2200 K, introduced into the system can significantly decrease the amount of non-metallic inclusions in the weld metal and so improve its mechanical properties

    Use of Technogenic Silica Fume and Brown Coal Semi-Coke in the Technology of Silicon Carbide

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    The paper describes thermodynamic experiments to determine the optimal temperature and time modes for the carbide production process from the briquette charge comprising silica fume and brown coal semi-coke, conditions for chemical enriching of silicon carbide, its phase, chemical and granulometric compositions and particle morphology

    Mathematical modeling of agricultural machinery technical maintenance

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    They developed the mathematical model of the maintenance system for the functional systems of machines and equipment the implementation of which will reduce the cost of the labor hour of maintenance and repair and justify the economically feasible level of the technical readiness coefficient. Modeling is the basis for automated system creation to improve the performance of agricultural machinery application.Keywords: technological system, machinery and equipment, maintenance, mathematicalmodel

    Titanium Carbide: Nanotechnology, Properties, Application

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    The paper develops scientific and technological bases for fabrication of titanium carbide which is a nanocomponent of composite materials. The authors determine optimum technology specifications and the main titanium carbide properties: fineness of titaniferous raw materials, carbide-forming agent quantity, set temperature of plasma flow, tempering temperature, titanium carbide yield, productivity, specific surface, size and shape of particles. The paper includes equations to describe how the major specifications of the fabrication technique influence the content of titanium carbide and free carbon in the end product

    Optimizing Technological Parameters of the Reduction Processes in Treating Steels in a Ladle Furnace

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    This work reports the possible development of reduction processes when treating the molten metal and slag using a ladle furnace under conditions of intensive stirring with an inert gas. The industrial data have been received, confirming the possibility of decreasing the concentration of ferrous and manganese oxides in the slag and stabilizing the contents of manganese and silicon in the metal
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